When add a struct element to TArray in UE4, Editor Crash

This is my Struct declaration. FEquipmentSlot has EquipmentClass and EquipmentCategory these two members, which store the item class and item category.

 USTRUCT(BlueprintType)
 struct FEquipmentSlot
 {
     GENERATED_BODY()
 
     UPROPERTY(EditAnywhere, BlueprintReadWrite)
     TSubclassOf<class APickupItem> EquipmentClass;
 
     UPROPERTY(EditAnywhere, BlueprintReadWrite)
     PickupItemCategory EquipmentCategory;
 
     FEquipmentSlot() : EquipmentClass(), EquipmentCategory(PickupItemCategory::ABILITY) {}
 
     FEquipmentSlot(TSubclassOf<APickupItem> Class, PickupItemCategory Category)
     {
         EquipmentClass = Class;
         EquipmentCategory = Category;
     }
 
 };

And this is my function, I want to construct a struct by passed parameters and add it to TArray

 void UEquipmentComponent::AddEquipmentSlot(TSubclassOf<APickupItem> Class, PickupItemCategory Category)
 {
         //EquipmentSlots is declared as TArray<FEquipmentSlot> type
         EquipmentSlots.Add(FEquipmentSlot(Class, Category));
 
         UE_LOG(LogTemp, Warning, TEXT("Add Equipment Slot Success"))
 }

Then I call this function like this

 AddEquipmentSlot(this->StaticClass(), Category);

Editor will crash, and this is error message

 Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x000000c8

I'm new to UE4 c++, and I search many answers but seems there is no right answer for this problem. Can anybody help me? Any suggestion will be very helpful.